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By Alec C. Bloem

A 55' deep excavation encompassing almost a city block in London, Ontario required a lateral earth retention system to provide both temporary excavation support and a permanent groundwater cut-off wall for a proposed office complex. The system selected was an interlocking Drilled Shaft wall with 3-4 levels of tiebacks. The specifications required the system to be designed for movements or settlements around the excavation of ¼" max. Design to be by the Contractor with design parameters and a comprehensive soils report provided. An extensive system of instrumentation in the form of inclinometers and survey targets were used to monitor vertical and horizontal movements of the shoring system and adjacent properties. Introduction The project, One London Place, is a two phase office tower development in downtown London, Ontario. Phase one consists of a 24 storey office tower on the northwest part of the site, with five levels of below ground parking over the entire site "Figure 1". A second office tower will be constructed at a future date.

Jan 1, 1991

By George Mylonakis

The curvatures and subsequent bending imposed to piles by the surrounding soil during the passage of strong seismic waves is studied. This type of bending develops even in the absence of a superstructure and is referred to as "kinematic bending", to distinguish it from bending imposed to piles by loads generated from the inertia of the superstructure ("inertial bending"). Although kinematic loading may be severe in the presence of sharp stiffness discontinuities in the profile and may lead to damage, it has received little attention by engineers. The scope of the paper is twofold: (i) to discuss some fundamental aspects of seismic pile bending, and (ii) to review some existing design methods. To this end, a dimensionless bending strain parameter (instead of the more commonly used bending moment), and a strain transmissibility function relating pile bending strain and corresponding soil shear strain are introduced. Numerical examples are also presented.

Jan 1, 2002

By Ralphie Adams, Tiana Rasmussen, Ashley E. Shirer

Transmission line foundation designers must rely on limited subsurface information, from easily accessible locations, resulting in subsurface uncertainty, increased design risk and increased construction costs. This paper presents a different approach for foundation analysis conducted in mountainous and alluvial floodplains located northwest of Phoenix, AZ. The region is dominated by fault-bounded, northeast dipping mountain ranges, where rock types and drillability can vary from granite to intact basalt. The valleys between are comprised of “basin-fill” deposits ranging from conglomerates and cemented soils to lose alluvium. Recently deposited alluvial fills can vary in depth significantly from location to location due to erosion and deposition from active and historic hydraulic features. To limit the subsurface uncertainty for foundation design, a phased approach using geophysical surveys along with detailed geologic reconnaissance was employed. Both compression wave and shear wave velocities were measured in order to identify the depth and properties of loose erodible materials from more scourresistant cemented, conglomerate, and rock deposits. These analyses were used in combination with limited subsurface drilling and sampling to evaluate direct embedment steel pole foundations for over fifty structures. Post analysis results from limited construction drilling reports were used to assess this approach.

Sep 8, 2021

By Joanna Bzówka

Nowadays, there are some new requirements for the supermarket floors. The floors are loaded by high point- and moving-loads. In spite of this fact, it is necessary to ensure the stiffness of the floor and the stiffness of its support. When pile foundations are designed in the case of weak soil, the piles are recommended under the foundations of the supermarket and also under the floor layers. The example of foundation of a typical supermarket located on long­standing municipal dumping ground is presented. Indirect foundation - CFA piles, 0.5 m in diameter and 4.5 to 20.0 m long, was de­signed. Fifteen trial loading tests were carried out.

Jan 1, 2006

By S. L. Karunakaran

Selection of an appropriate foundation system requires great skill and ingenuity on the part of the designer. Certain guidelines for choosing between a pile and raft foundation are presented. A number of methods are available for estimating the capacity of piles, giving a wide range of values for the theoretical load carrying capacity. A few aspects to be taken into account while arriving at an appropriate theoretical capacity are discussed. The effect of fluctuation of water table level on the pile capacity and method of accounting for this factor on the pile capacity obtained through initial load test are also discussed. A case study presents a comparison between the estimated values of capacity of piles and the values obtained through the initial load test.

Jan 1, 1996

By Roy Jennings

The Discovery Expedition of St. Charles, MO chose to build its two-story museum in the flood plain of the Missouri River, near the starting point of the Lewis and Clark Expedition. Should the lower level be inundated at flood stage, plans call for the replica riverboats to be moved by trailer to higher ground. The museum's design required an open span structure with heavily loaded footing or piles. Spread footings could not be used due to the compressible soil profile. The location, in a historical district, precluded dynamically driven piles. Sixty-three uncased Helical Pulldown Micropiles were driven to the bearing stratum to support the museum with minimum disturbance. There were no spoils to dispose of during construction and the piles were completed in eight working days with minimum impact to the environment and neighborhood. The maximum working load required was 84,000 pounds (374kN). Test results are given in the form of installing torque.

Jan 1, 2003

By M. Zanotto

[ ] A period of heavy rains caused the river Adda to flood parts of the Valtellina, one of the Alpine valleys of Northern Italy. The exceptionally high waters put under considerable strain the whole system of embankments and levees controlling the river and protecting the adjacent towns and lands. In some places the water breached and washed away the embankments, submerging large tracts of cultivated land, buildings, roads and railway tracks. The town of Talamona, in the lower Valtellina, was hit particularly hard: in its proximity the river overrun and then washed away 300 m (1,000 ft) of embankment (see vicinity map, fig. 2), depositing large amounts of riverbed debris onto over 400 hectares (1,000 acres) of fertile land.

Jan 1, 1992

By Wendy L. Mathieson

The Bonneville Power Administration (BPA) will build about 500 miles of new 500-kV transmission lines in the next 5 years. Many new lattice towers will be built in remote locations or in environmentally sensitive areas. Therefore, micropile foundations were designed that could be installed in remote areas, in variable subsurface conditions, and in a manner that would reduce excavation volumes and potential erosion concerns. Typical lattice tower foundation axial loads range between 75 and 1,500 kips (300 to 6,700 kilonewtons [kN]) per leg, with uplift loads being slightly less than compressive loads. Lateral loads range from 5 to 320 kips (20 to 1,400 kN) per leg. Full-scale axial and lateral load tests were conducted in geologically representative soil units during the micropile design for the 9-mile-long (14-kilometer [km]), Kangley-Echo Lake transmission line that extends through a protected watershed east of Seattle, Washington. Micropile foundations for single and double circuit suspension and dead end towers were designed using these load test data.

Jan 1, 2004

By Darrell Wilder

When designing excavation support systems in urban environments, it is often necessary to consider the effect of vertical surcharge loads from adjacent structures. Several methods are used in practice to establish the horizontal surcharge-induce pressure on the excavation support. According to the experience of the authors, these methods often seem to overestimate the effect of the surcharge and may have significant impact on the construction costs. This paper explores several of these procedures and provides a discussion as to the reasons for the differences in surcharge effect predictions between different procedures. It also provides practical recommendations for designers dealing with excavation support design.

Jan 1, 2006

By P. Bermingham

A new approach to load testing of high capacity piles is presented. The method is mobile, inexpensive, repeatable and non-destructive allowing for multiple pile testing at a single site. A reaction mass is placed over a pressure chamber situated atop the pile to be tested. The test method is significant in that it can produce linearly increasing forces of high magnitude (over 5.0 MN) with durations of up to 80 milliseconds. This represents pulse durations an order of magnitude longer than achieved using a drop hammer. The accelerations the pile undergoes are less than one g, (conventional dynamic methods = 50 to 100 g). These effects combine to produce pile behaviour no longer dominated by the action of stress wave, instead the pile is under high levels of stress through its length during the force input. This is representative of the situation when static loads are applied, thus the method may be considered quasi-static. Further advances introduced with this method are that pile deflection and transmitted force are measured directly by means of a laser beam and load cell. This allows accurate correlation of event load displacement histories without the error associated with zero shift (acceleration integration) or non-homogeneous materials (strain measurement). The load displacement histories emulate those obtained for static load testing.

Jan 1, 1989

By Michael D. Justason

This paper details the static and Statnamic load testing on a 600 mm square pre-stressed concrete pile. The pile was located at Pier 15 on the 20 million-dollar Bayou Chico Bridge Project in Pensacola, Florida. The pile was 10.5 meters long and had a design load of 1.3 MN. Three static load test cycles were performed in November, 1996. The Statnamic load test was performed in January, 1997. The Davisson Failure load of the first cycle of the static test was 3.7 MN, and the Davisson Failure load of the Statnamic test was 3.2 MN. The load-displacement curves for the two types of tests were very similar, indicating that the Statnamic load test performed well in the sandy soils. Strain gauges embedded in the pile showed 35% skin friction and 65% end bearing for both test methods. Strain gauges were located at equal spacing at five elevations in the pile. A toe accelerometer verified the rigid body assumption of the Unloading Point Method currently used in the analysis of Statnamic load tests. The data collected from the pile instrumentation was of excellent quality and represents some of the best research to date comparing static and Statnamic load tests.

Jan 1, 1997

By Scott White, Pishun Tantivangphaisal, Andrew Bell, Chris Barker

There has been considerable advancement in recent years in the tools, both software and hardware, available to allow efficient digitalization of site records during the construction of geotechnical works. Whilst these tools have excelled at replacing handwritten records, the ability to use digital records to validate design and construction requirements in real time or even within reasonable timescales has generally been limited to the development of bespoke ‘prototype’ project specific solutions. This paper describes the development and implementation of an industry standard design schedule and the benefits of the broad adoption of a single database schema for data recorded on geotechnical sites. The former has brought significant improvements and automation of the design process, whilst the latter has enabled the validation of the constructed works against design intent in almost real time. Further details of the standardized design schedule, already publicly available in the UK through the FPS, examples and lessons learnt from implementing digital site record systems on live projects are presented herein. The utilization of cloud computing technology and complex algorithms linking plant/rig instrumentation with design data can further automate construction sites using IoT (Internet of Things) best practices. The authors will share their experience of the recent deployment of a digitalized design-to-construction record system, give recommendations for future development and a call for an industry wide drive to finalize and adopt the AGS Piling data schema.

May 1, 2022

By H. L. Jessberger

In recent years piled raft foundations of multi-storey buildings on weak soils have generated much interest and discussion. By taking account of the effects of each component of the system - the pile group and the raft - it is possible to reduce the settlements and inclinations of the system and to have an expedient load distribution on the piles and the raft. Thus the structural design of the foundation can be optimised.

Jan 1, 1991

By F. Castelli

A simplified non-linear method to predict the behaviour of a single pile and/or pile group under horizontal loads is presented in the paper. The evaluation of the non-linear lateral deflection is based on a procedure taking into account the decrease of the model stiffness with the increasing of the applied load. The solution derived firstly for the single pile, was extended to the case of a pile group introducing the p-multiplier (fm) concept proposed by Brown et al. (1988).

Jan 1, 2006

By JO Choi

Jet-grouting method is a useful technique to reinforce foundations on relatively soft or vulnerable soil layers such as fractured zone and stratum with cavities. Although jet-grouting has been widely applied to various field works, a reliable design standard has not been established yet. A number of model tests were performed to investigate end bearing behaviors of piles reinforced by jet-grouting. It was concluded that end bearing capacity was increased in proportion to uniaxial compressive strength of grout column. Based on the test results, the design criteria for the end bearing capacity were suggested.

Jan 1, 2006

By Robert Bittner

The following is a report on the development of two unique and separate cofferdam systems used in the construction of the marine foundations for the I-205 Columbia River Bridge at Portland, Oregon for the Oregon Department of Transportation. The first of these two systems utilized interlocking H-pile 100 ft long to form a cofferdam 145 ft by 58 ft in plan and 100 ft deep. The second system consisted of two immense bell shaped steel forms. The larger of the two forms was 83 ft by 66 ft in plan, 62 ft high and weighed 450 tons. This form was externally stiffened for a designed hydrostatic head of 54 ft. Both forms were designed, except for the top 14 ft, to be set and stripped in one solidly welded unit. The supporting geological formation for the bridge foundations is the Troutdale, a cemented sand and gravel. This formation is at the ground surface on the Washington Shore and slopes downward to a depth of 115 ft below normal high water at about mid-channel. In this area the Troutdale formation is covered with a layer of fine to medium sand 90 to 100 ft thick. It was the variable depth of the Troutdale which determined the two types of foundations and the corresponding to the two cofferdam systems.

Jan 1, 2013

By F. Schlosser

The extension of Montparnasse Station in Paris required the construction of supports of very high unit capacity to support a particularly rigid super-structure. The majority of the site is characterized by the existence of old limestone quarries at a depth of approximately 20 metres. These workings have been backfilled in some places, have collapsed in some places and have given rise to local subsidences in the marne layers above them. This paper addresses the steps taken by the group of companies and their consultants to evaluate the equivalent stiffnesses of the supports necessary for the design of the superstructure, and gives details of the construction techniques chosen by the foundations specialist to adapt to the particular conditions encountered on this site.

Jan 1, 1989

By Zhang Jiaju

For the highrise buildings with deep foundstion of irregular plane shape, an appropriate calculate model to the heave of foundation soil after excavation is proposed and studied using analytic method and FEM (Finite Element Method) respectively to provide an effective way for solving this kind engineering problem. Also combined with the practice of construction deep foundation of Capital Mansion, calculation of the heave of foundation soil after excavation is given. Compared these results from above two methods with the results measured in situ, it is conformal on the whole, and the results by FEM are much closer with the measured.

Jan 1, 1991

By W. Robert Thompson

Hurricane Katrina caused significant damage to transportation structures on the Gulf coast in August, 2005, including the destruction of the US 90 Bridge over Biloxi Bay, Mississippi. Part of the successful design/build proposal for the replacement bridge included a comprehensive test pile program of indicator piles and load test piles in the geotechnical investigation program. A total of 22 indicator piles were installed on the project using the pile driving analyzer to monitor the pile behavior. Five load tests were performed: two axial Statnamic, two lateral Statnamic, and one static axial. The results of the test pile program established driving criteria for production piles that included end-of-drive blow counts and pile tip elevations with an appropriate allowance for setup. The program also confirmed that the planned installation equipment and techniques of GC Constructors, a joint venture of Massman Construction Co., Kiewit Southern Co., and Traylor Bros., Inc., would install the piles to the design tip elevations before production piles began. An extensive program of restrike measurements at a range of times after initial driving of the indicator piles provided a systematic documentation of pile setup in the soil profiles on the site. These resistance values were used to develop a dimensionless setup factor ?S? as the ratio of the restrike resistance to the end of drive resistance. This factor varied from 1.5 for piles penetrating clays and tipped in sand to 3.0 for piles bearing completely in clay and helped establish an end-of drive blow count that included an allowance for setup. The CAPWAP analyses of restrike data with setup and the load test data were used to confirm the design unit side shear and end bearing values developed from the borings and static capacity calculations and to select the design pile lengths.

Jan 1, 2009

By Padmavathi V. Sagi

In this paper, effect of cyclic loading on the behavior of a long, flexible, unrestrained vertical pile loaded laterally in soft clay is examined. For cyclic loading, the analysis is carried out using a new method for the construction of p-y curves and for static loading conditions, p-y curves proposed by Dewaikar and Poonam (2005) are used. An iterative analysis is employed with secant modulus approach using a matrix method known as moment area method developed by Sawant et al. (1994). For pile top deflection of 20% of pile diameter, the load values are computed for both static and cyclic conditions. The comparison of results with the field test results reported by Matlock (1970) shows a good agreement. A parametric study is further carried out to examine the effect of load eccentricity, pile embedment length, diameter and the number of cycles on the pile response. The results of this study are discussed in the paper.

Jan 1, 2006